Prior art information management systems, such as the one labeled 100 in FIG. 1, have been developed to electronically store digital representation of documents. Referring to FIG. 1, the system 100 is typically implemented via a local area network (LAN) 102. The network 100 contains one or more servers 104 and 106 for controlling the storage and retrieval of digital documents in a document storage memory 108.
The system 100 includes a number of users connected via several microcomputers or other types of computer terminals 110, 114, 116, and 118. A user desiring to electronically store a document can have the document scanned by a commercially available document scanner 112, which converts the document into a digital representation--perhaps a bit map of "1's" and "0's". The digitized document is transmitted via a microcomputer 110 over the network 102 to the servers 104 and 106.
The servers control the flow of information on the network 100, and are responsible for storing documents in a document storage area 108. The document storage area 108 can be a variety of memory storage devices as are known in the art. During a document retrieval operation, a user requests, via the servers, a particular document from memory 108. When the user's request is the next in the queue, the servers request the information from all of the memory locations comprising the requested document and integrate the information according to a stored linked list (linking all of the memory locations having information making up the document in question) for the document.
The servers forward the requested document to the microcomputer for the user's viewing and/or storage.
In prior art systems 100, a request for viewing (only) a document entails receiving the entire contents of the document by a terminal with sufficient processing power, cache and storage memory capacity (a "thick" computer). Alternatively, a low-end terminal can work suffficiently with the aid of a server, but will have viewing delays for large documents.
When prior art systems involve remote storage and retrieval rather than via a closed LAN, several problems are encountered. When a user wishes to view a stored document in such a remote storage/retrieval system, the user must either have a thick computer, or must be connected to a local server which gives the user an acceptable level of virtual computing power. Servers not only contain expensive hardware, but need expensive and time-consuming software maintenance. In either case, the communication link in such a system must use a high bandwidth to handle the capacity of information needed to make retrieval times for document viewing palatable.
Because of potential delays in viewing documents, prior art remote, document storage/retrieval systems do not allow for the participation of user's with stand-alone "thin" computers (those with lower computing power) at desirable retrieval speeds. Therefore, what is desired but not present in prior art remote document storage and retrieval systems, is one which allows the efficient participation of stand-alone "thin" users. That is, a system which allows for rapid displaying of stored documents--even where the user has a thin computer--and a low-bandwidth communication link.
The best prior art approaches have generally addressed the above problems in one of two ways. In a first approach, the host computer slices a document image into a multiplicity of strips--for example, one-inch wide. The entire image and the image strips are placed in mass storage. During a document retrieval operation, the user can view one or more strips (one at a time) of a document to keep from having to download the entire document while the user is deciding whether a particular document is of interest. This approach, however, does not improve the downloading speed, requires considerably more mass storage area, and a single strip is not always sufficient to decide whether the document should be downloaded.
In a second approach, the host computer creates and stores with each document, a number of indexed images with various pre-determined screen resolutions. It may also contain a number of tiles from each image which can be viewed in a zoom-in mode. In this approach, the user is limited to choosing from a fixed number of screen resolution versions of a desired document, which may not match the users actual resolution or panel size. Further, the borders of the zoom-in tiles may not be where they are most desired by the user. The need to create many special case image files, increased document storage area requirement, and less than optimum user flexibility make this complicated approach also problematic.
Several prior art patents are related to the present invention, although all contain the above-identified shortcomings.
U.S. Pat. No. 5,666,215 to Fredlund, et al. (issued Sep. 9, 1997), although not an information management system, or even a document image management system, discloses a system for allowing a customer to remotely view "positives" and order desired photographs from a central picture development entity, the positives being made from scanned negatives of the customer's camera film.
U.S. Pat. No. 5,440,401 to Parulski, et al. (issued Aug. 8, 1995), discloses a digital image system for storing in a common database of a storage medium (such as a CD, etc.), a file of a group of high-resolution images, along with an index data file with a montage of low-resolution "thumbnail" pictures of each of the high-resolution images. Each low-resolution thumbnail has an identifier which points to the associated high-resolution image.
U.S. Pat. No. 5,381,526 to Ellson (issued Jan. 10, 1995), discloses a digital imaging method/system in which an image is stored as two or more different linked image units on a storage medium, so that upon retrieval of the image, the image units can be combined for effects such as three-dimensional views, etc. The image units for an image can contain, for example, luminance and chrominance information in a first image unit, and pixel range information in a second linked image unit.
U.S. Pat. No. 5,414,811 to Parulski, et al. (issued May 9, 1995), discloses a digital image system for reducing the latency time of retrieving images from a storage medium such as a compact disc. When a particular image is downloaded into a user's image memory, adjacent images in the image database are also loaded into the image memory, so that if the user later wishes to retrieve one of the adjacent images, it need not be downloaded from the storage medium, and can thus be more rapidly displayed.
U.S. Pat. No. 5,235,654 to Anderson, et al. (issued Aug. 10, 1993), discloses an electronic document storage and retrieval system for allowing a user, via a workstation, to freely choose the form of a document to be generated from a common database of a host processor.
U.S. Pat. No. 5,200,993 to Wheeler, et al. (issued Apr. 6, 1993), discloses a public telephone-networked digital imaging system in which the communication protocol of the local network is converted to the communication protocol of the "backbone" network. Automatic Number Identification data is used to identify remote terminals.
U.S. Pat. No. 5,550,976 to Henderson, et al. (issued Aug. 27, 1996), discloses an electronic data management system of networked computers wherein data processing among the computers is asynchronous.
U.S. Pat. No. 5,235,680 to Bijnagte (issued Aug. 10, 1993), discloses a system limited to remote access to a centralized computer for the storage and retrieval of real estate listing information including images of property listed for sale.
U.S. Pat. No. 5,502,576 to Ramsay, et al. (issued Mar. 26, 1996), discloses a hybrid document imaging system using both digital and analog signals and signal processing to purportedly remove process speed limitations of digital signals while improving the resolution and precision problems associated with analog signals.